xref: /openbmc/linux/drivers/leds/leds-lp5523.c (revision 5f32c314)
1 /*
2  * lp5523.c - LP5523 LED Driver
3  *
4  * Copyright (C) 2010 Nokia Corporation
5  * Copyright (C) 2012 Texas Instruments
6  *
7  * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
8  *          Milo(Woogyom) Kim <milo.kim@ti.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  */
24 
25 #include <linux/delay.h>
26 #include <linux/firmware.h>
27 #include <linux/i2c.h>
28 #include <linux/init.h>
29 #include <linux/leds.h>
30 #include <linux/module.h>
31 #include <linux/mutex.h>
32 #include <linux/of.h>
33 #include <linux/platform_data/leds-lp55xx.h>
34 #include <linux/slab.h>
35 
36 #include "leds-lp55xx-common.h"
37 
38 #define LP5523_PROGRAM_LENGTH		32	/* bytes */
39 /* Memory is used like this:
40    0x00 engine 1 program
41    0x10 engine 2 program
42    0x20 engine 3 program
43    0x30 engine 1 muxing info
44    0x40 engine 2 muxing info
45    0x50 engine 3 muxing info
46 */
47 #define LP5523_MAX_LEDS			9
48 
49 /* Registers */
50 #define LP5523_REG_ENABLE		0x00
51 #define LP5523_REG_OP_MODE		0x01
52 #define LP5523_REG_ENABLE_LEDS_MSB	0x04
53 #define LP5523_REG_ENABLE_LEDS_LSB	0x05
54 #define LP5523_REG_LED_PWM_BASE		0x16
55 #define LP5523_REG_LED_CURRENT_BASE	0x26
56 #define LP5523_REG_CONFIG		0x36
57 #define LP5523_REG_STATUS		0x3A
58 #define LP5523_REG_RESET		0x3D
59 #define LP5523_REG_LED_TEST_CTRL	0x41
60 #define LP5523_REG_LED_TEST_ADC		0x42
61 #define LP5523_REG_CH1_PROG_START	0x4C
62 #define LP5523_REG_CH2_PROG_START	0x4D
63 #define LP5523_REG_CH3_PROG_START	0x4E
64 #define LP5523_REG_PROG_PAGE_SEL	0x4F
65 #define LP5523_REG_PROG_MEM		0x50
66 
67 /* Bit description in registers */
68 #define LP5523_ENABLE			0x40
69 #define LP5523_AUTO_INC			0x40
70 #define LP5523_PWR_SAVE			0x20
71 #define LP5523_PWM_PWR_SAVE		0x04
72 #define LP5523_CP_AUTO			0x18
73 #define LP5523_AUTO_CLK			0x02
74 
75 #define LP5523_EN_LEDTEST		0x80
76 #define LP5523_LEDTEST_DONE		0x80
77 #define LP5523_RESET			0xFF
78 #define LP5523_ADC_SHORTCIRC_LIM	80
79 #define LP5523_EXT_CLK_USED		0x08
80 #define LP5523_ENG_STATUS_MASK		0x07
81 
82 /* Memory Page Selection */
83 #define LP5523_PAGE_ENG1		0
84 #define LP5523_PAGE_ENG2		1
85 #define LP5523_PAGE_ENG3		2
86 #define LP5523_PAGE_MUX1		3
87 #define LP5523_PAGE_MUX2		4
88 #define LP5523_PAGE_MUX3		5
89 
90 /* Program Memory Operations */
91 #define LP5523_MODE_ENG1_M		0x30	/* Operation Mode Register */
92 #define LP5523_MODE_ENG2_M		0x0C
93 #define LP5523_MODE_ENG3_M		0x03
94 #define LP5523_LOAD_ENG1		0x10
95 #define LP5523_LOAD_ENG2		0x04
96 #define LP5523_LOAD_ENG3		0x01
97 
98 #define LP5523_ENG1_IS_LOADING(mode)	\
99 	((mode & LP5523_MODE_ENG1_M) == LP5523_LOAD_ENG1)
100 #define LP5523_ENG2_IS_LOADING(mode)	\
101 	((mode & LP5523_MODE_ENG2_M) == LP5523_LOAD_ENG2)
102 #define LP5523_ENG3_IS_LOADING(mode)	\
103 	((mode & LP5523_MODE_ENG3_M) == LP5523_LOAD_ENG3)
104 
105 #define LP5523_EXEC_ENG1_M		0x30	/* Enable Register */
106 #define LP5523_EXEC_ENG2_M		0x0C
107 #define LP5523_EXEC_ENG3_M		0x03
108 #define LP5523_EXEC_M			0x3F
109 #define LP5523_RUN_ENG1			0x20
110 #define LP5523_RUN_ENG2			0x08
111 #define LP5523_RUN_ENG3			0x02
112 
113 #define LED_ACTIVE(mux, led)		(!!(mux & (0x0001 << led)))
114 
115 enum lp5523_chip_id {
116 	LP5523,
117 	LP55231,
118 };
119 
120 static int lp5523_init_program_engine(struct lp55xx_chip *chip);
121 
122 static inline void lp5523_wait_opmode_done(void)
123 {
124 	usleep_range(1000, 2000);
125 }
126 
127 static void lp5523_set_led_current(struct lp55xx_led *led, u8 led_current)
128 {
129 	led->led_current = led_current;
130 	lp55xx_write(led->chip, LP5523_REG_LED_CURRENT_BASE + led->chan_nr,
131 		led_current);
132 }
133 
134 static int lp5523_post_init_device(struct lp55xx_chip *chip)
135 {
136 	int ret;
137 
138 	ret = lp55xx_write(chip, LP5523_REG_ENABLE, LP5523_ENABLE);
139 	if (ret)
140 		return ret;
141 
142 	/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
143 	usleep_range(1000, 2000);
144 
145 	ret = lp55xx_write(chip, LP5523_REG_CONFIG,
146 			    LP5523_AUTO_INC | LP5523_PWR_SAVE |
147 			    LP5523_CP_AUTO | LP5523_AUTO_CLK |
148 			    LP5523_PWM_PWR_SAVE);
149 	if (ret)
150 		return ret;
151 
152 	/* turn on all leds */
153 	ret = lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_MSB, 0x01);
154 	if (ret)
155 		return ret;
156 
157 	ret = lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_LSB, 0xff);
158 	if (ret)
159 		return ret;
160 
161 	return lp5523_init_program_engine(chip);
162 }
163 
164 static void lp5523_load_engine(struct lp55xx_chip *chip)
165 {
166 	enum lp55xx_engine_index idx = chip->engine_idx;
167 	u8 mask[] = {
168 		[LP55XX_ENGINE_1] = LP5523_MODE_ENG1_M,
169 		[LP55XX_ENGINE_2] = LP5523_MODE_ENG2_M,
170 		[LP55XX_ENGINE_3] = LP5523_MODE_ENG3_M,
171 	};
172 
173 	u8 val[] = {
174 		[LP55XX_ENGINE_1] = LP5523_LOAD_ENG1,
175 		[LP55XX_ENGINE_2] = LP5523_LOAD_ENG2,
176 		[LP55XX_ENGINE_3] = LP5523_LOAD_ENG3,
177 	};
178 
179 	lp55xx_update_bits(chip, LP5523_REG_OP_MODE, mask[idx], val[idx]);
180 
181 	lp5523_wait_opmode_done();
182 }
183 
184 static void lp5523_load_engine_and_select_page(struct lp55xx_chip *chip)
185 {
186 	enum lp55xx_engine_index idx = chip->engine_idx;
187 	u8 page_sel[] = {
188 		[LP55XX_ENGINE_1] = LP5523_PAGE_ENG1,
189 		[LP55XX_ENGINE_2] = LP5523_PAGE_ENG2,
190 		[LP55XX_ENGINE_3] = LP5523_PAGE_ENG3,
191 	};
192 
193 	lp5523_load_engine(chip);
194 
195 	lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, page_sel[idx]);
196 }
197 
198 static void lp5523_stop_all_engines(struct lp55xx_chip *chip)
199 {
200 	lp55xx_write(chip, LP5523_REG_OP_MODE, 0);
201 	lp5523_wait_opmode_done();
202 }
203 
204 static void lp5523_stop_engine(struct lp55xx_chip *chip)
205 {
206 	enum lp55xx_engine_index idx = chip->engine_idx;
207 	u8 mask[] = {
208 		[LP55XX_ENGINE_1] = LP5523_MODE_ENG1_M,
209 		[LP55XX_ENGINE_2] = LP5523_MODE_ENG2_M,
210 		[LP55XX_ENGINE_3] = LP5523_MODE_ENG3_M,
211 	};
212 
213 	lp55xx_update_bits(chip, LP5523_REG_OP_MODE, mask[idx], 0);
214 
215 	lp5523_wait_opmode_done();
216 }
217 
218 static void lp5523_turn_off_channels(struct lp55xx_chip *chip)
219 {
220 	int i;
221 
222 	for (i = 0; i < LP5523_MAX_LEDS; i++)
223 		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0);
224 }
225 
226 static void lp5523_run_engine(struct lp55xx_chip *chip, bool start)
227 {
228 	int ret;
229 	u8 mode;
230 	u8 exec;
231 
232 	/* stop engine */
233 	if (!start) {
234 		lp5523_stop_engine(chip);
235 		lp5523_turn_off_channels(chip);
236 		return;
237 	}
238 
239 	/*
240 	 * To run the engine,
241 	 * operation mode and enable register should updated at the same time
242 	 */
243 
244 	ret = lp55xx_read(chip, LP5523_REG_OP_MODE, &mode);
245 	if (ret)
246 		return;
247 
248 	ret = lp55xx_read(chip, LP5523_REG_ENABLE, &exec);
249 	if (ret)
250 		return;
251 
252 	/* change operation mode to RUN only when each engine is loading */
253 	if (LP5523_ENG1_IS_LOADING(mode)) {
254 		mode = (mode & ~LP5523_MODE_ENG1_M) | LP5523_RUN_ENG1;
255 		exec = (exec & ~LP5523_EXEC_ENG1_M) | LP5523_RUN_ENG1;
256 	}
257 
258 	if (LP5523_ENG2_IS_LOADING(mode)) {
259 		mode = (mode & ~LP5523_MODE_ENG2_M) | LP5523_RUN_ENG2;
260 		exec = (exec & ~LP5523_EXEC_ENG2_M) | LP5523_RUN_ENG2;
261 	}
262 
263 	if (LP5523_ENG3_IS_LOADING(mode)) {
264 		mode = (mode & ~LP5523_MODE_ENG3_M) | LP5523_RUN_ENG3;
265 		exec = (exec & ~LP5523_EXEC_ENG3_M) | LP5523_RUN_ENG3;
266 	}
267 
268 	lp55xx_write(chip, LP5523_REG_OP_MODE, mode);
269 	lp5523_wait_opmode_done();
270 
271 	lp55xx_update_bits(chip, LP5523_REG_ENABLE, LP5523_EXEC_M, exec);
272 }
273 
274 static int lp5523_init_program_engine(struct lp55xx_chip *chip)
275 {
276 	int i;
277 	int j;
278 	int ret;
279 	u8 status;
280 	/* one pattern per engine setting LED MUX start and stop addresses */
281 	static const u8 pattern[][LP5523_PROGRAM_LENGTH] =  {
282 		{ 0x9c, 0x30, 0x9c, 0xb0, 0x9d, 0x80, 0xd8, 0x00, 0},
283 		{ 0x9c, 0x40, 0x9c, 0xc0, 0x9d, 0x80, 0xd8, 0x00, 0},
284 		{ 0x9c, 0x50, 0x9c, 0xd0, 0x9d, 0x80, 0xd8, 0x00, 0},
285 	};
286 
287 	/* hardcode 32 bytes of memory for each engine from program memory */
288 	ret = lp55xx_write(chip, LP5523_REG_CH1_PROG_START, 0x00);
289 	if (ret)
290 		return ret;
291 
292 	ret = lp55xx_write(chip, LP5523_REG_CH2_PROG_START, 0x10);
293 	if (ret)
294 		return ret;
295 
296 	ret = lp55xx_write(chip, LP5523_REG_CH3_PROG_START, 0x20);
297 	if (ret)
298 		return ret;
299 
300 	/* write LED MUX address space for each engine */
301 	for (i = LP55XX_ENGINE_1; i <= LP55XX_ENGINE_3; i++) {
302 		chip->engine_idx = i;
303 		lp5523_load_engine_and_select_page(chip);
304 
305 		for (j = 0; j < LP5523_PROGRAM_LENGTH; j++) {
306 			ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + j,
307 					pattern[i - 1][j]);
308 			if (ret)
309 				goto out;
310 		}
311 	}
312 
313 	lp5523_run_engine(chip, true);
314 
315 	/* Let the programs run for couple of ms and check the engine status */
316 	usleep_range(3000, 6000);
317 	lp55xx_read(chip, LP5523_REG_STATUS, &status);
318 	status &= LP5523_ENG_STATUS_MASK;
319 
320 	if (status != LP5523_ENG_STATUS_MASK) {
321 		dev_err(&chip->cl->dev,
322 			"cound not configure LED engine, status = 0x%.2x\n",
323 			status);
324 		ret = -1;
325 	}
326 
327 out:
328 	lp5523_stop_all_engines(chip);
329 	return ret;
330 }
331 
332 static int lp5523_update_program_memory(struct lp55xx_chip *chip,
333 					const u8 *data, size_t size)
334 {
335 	u8 pattern[LP5523_PROGRAM_LENGTH] = {0};
336 	unsigned cmd;
337 	char c[3];
338 	int nrchars;
339 	int ret;
340 	int offset = 0;
341 	int i = 0;
342 
343 	while ((offset < size - 1) && (i < LP5523_PROGRAM_LENGTH)) {
344 		/* separate sscanfs because length is working only for %s */
345 		ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
346 		if (ret != 1)
347 			goto err;
348 
349 		ret = sscanf(c, "%2x", &cmd);
350 		if (ret != 1)
351 			goto err;
352 
353 		pattern[i] = (u8)cmd;
354 		offset += nrchars;
355 		i++;
356 	}
357 
358 	/* Each instruction is 16bit long. Check that length is even */
359 	if (i % 2)
360 		goto err;
361 
362 	for (i = 0; i < LP5523_PROGRAM_LENGTH; i++) {
363 		ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + i, pattern[i]);
364 		if (ret)
365 			return -EINVAL;
366 	}
367 
368 	return size;
369 
370 err:
371 	dev_err(&chip->cl->dev, "wrong pattern format\n");
372 	return -EINVAL;
373 }
374 
375 static void lp5523_firmware_loaded(struct lp55xx_chip *chip)
376 {
377 	const struct firmware *fw = chip->fw;
378 
379 	if (fw->size > LP5523_PROGRAM_LENGTH) {
380 		dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
381 			fw->size);
382 		return;
383 	}
384 
385 	/*
386 	 * Program momery sequence
387 	 *  1) set engine mode to "LOAD"
388 	 *  2) write firmware data into program memory
389 	 */
390 
391 	lp5523_load_engine_and_select_page(chip);
392 	lp5523_update_program_memory(chip, fw->data, fw->size);
393 }
394 
395 static ssize_t show_engine_mode(struct device *dev,
396 				struct device_attribute *attr,
397 				char *buf, int nr)
398 {
399 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
400 	struct lp55xx_chip *chip = led->chip;
401 	enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
402 
403 	switch (mode) {
404 	case LP55XX_ENGINE_RUN:
405 		return sprintf(buf, "run\n");
406 	case LP55XX_ENGINE_LOAD:
407 		return sprintf(buf, "load\n");
408 	case LP55XX_ENGINE_DISABLED:
409 	default:
410 		return sprintf(buf, "disabled\n");
411 	}
412 }
413 show_mode(1)
414 show_mode(2)
415 show_mode(3)
416 
417 static ssize_t store_engine_mode(struct device *dev,
418 				 struct device_attribute *attr,
419 				 const char *buf, size_t len, int nr)
420 {
421 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
422 	struct lp55xx_chip *chip = led->chip;
423 	struct lp55xx_engine *engine = &chip->engines[nr - 1];
424 
425 	mutex_lock(&chip->lock);
426 
427 	chip->engine_idx = nr;
428 
429 	if (!strncmp(buf, "run", 3)) {
430 		lp5523_run_engine(chip, true);
431 		engine->mode = LP55XX_ENGINE_RUN;
432 	} else if (!strncmp(buf, "load", 4)) {
433 		lp5523_stop_engine(chip);
434 		lp5523_load_engine(chip);
435 		engine->mode = LP55XX_ENGINE_LOAD;
436 	} else if (!strncmp(buf, "disabled", 8)) {
437 		lp5523_stop_engine(chip);
438 		engine->mode = LP55XX_ENGINE_DISABLED;
439 	}
440 
441 	mutex_unlock(&chip->lock);
442 
443 	return len;
444 }
445 store_mode(1)
446 store_mode(2)
447 store_mode(3)
448 
449 static int lp5523_mux_parse(const char *buf, u16 *mux, size_t len)
450 {
451 	u16 tmp_mux = 0;
452 	int i;
453 
454 	len = min_t(int, len, LP5523_MAX_LEDS);
455 
456 	for (i = 0; i < len; i++) {
457 		switch (buf[i]) {
458 		case '1':
459 			tmp_mux |= (1 << i);
460 			break;
461 		case '0':
462 			break;
463 		case '\n':
464 			i = len;
465 			break;
466 		default:
467 			return -1;
468 		}
469 	}
470 	*mux = tmp_mux;
471 
472 	return 0;
473 }
474 
475 static void lp5523_mux_to_array(u16 led_mux, char *array)
476 {
477 	int i, pos = 0;
478 	for (i = 0; i < LP5523_MAX_LEDS; i++)
479 		pos += sprintf(array + pos, "%x", LED_ACTIVE(led_mux, i));
480 
481 	array[pos] = '\0';
482 }
483 
484 static ssize_t show_engine_leds(struct device *dev,
485 			    struct device_attribute *attr,
486 			    char *buf, int nr)
487 {
488 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
489 	struct lp55xx_chip *chip = led->chip;
490 	char mux[LP5523_MAX_LEDS + 1];
491 
492 	lp5523_mux_to_array(chip->engines[nr - 1].led_mux, mux);
493 
494 	return sprintf(buf, "%s\n", mux);
495 }
496 show_leds(1)
497 show_leds(2)
498 show_leds(3)
499 
500 static int lp5523_load_mux(struct lp55xx_chip *chip, u16 mux, int nr)
501 {
502 	struct lp55xx_engine *engine = &chip->engines[nr - 1];
503 	int ret;
504 	u8 mux_page[] = {
505 		[LP55XX_ENGINE_1] = LP5523_PAGE_MUX1,
506 		[LP55XX_ENGINE_2] = LP5523_PAGE_MUX2,
507 		[LP55XX_ENGINE_3] = LP5523_PAGE_MUX3,
508 	};
509 
510 	lp5523_load_engine(chip);
511 
512 	ret = lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, mux_page[nr]);
513 	if (ret)
514 		return ret;
515 
516 	ret = lp55xx_write(chip, LP5523_REG_PROG_MEM , (u8)(mux >> 8));
517 	if (ret)
518 		return ret;
519 
520 	ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + 1, (u8)(mux));
521 	if (ret)
522 		return ret;
523 
524 	engine->led_mux = mux;
525 	return 0;
526 }
527 
528 static ssize_t store_engine_leds(struct device *dev,
529 			     struct device_attribute *attr,
530 			     const char *buf, size_t len, int nr)
531 {
532 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
533 	struct lp55xx_chip *chip = led->chip;
534 	struct lp55xx_engine *engine = &chip->engines[nr - 1];
535 	u16 mux = 0;
536 	ssize_t ret;
537 
538 	if (lp5523_mux_parse(buf, &mux, len))
539 		return -EINVAL;
540 
541 	mutex_lock(&chip->lock);
542 
543 	chip->engine_idx = nr;
544 	ret = -EINVAL;
545 
546 	if (engine->mode != LP55XX_ENGINE_LOAD)
547 		goto leave;
548 
549 	if (lp5523_load_mux(chip, mux, nr))
550 		goto leave;
551 
552 	ret = len;
553 leave:
554 	mutex_unlock(&chip->lock);
555 	return ret;
556 }
557 store_leds(1)
558 store_leds(2)
559 store_leds(3)
560 
561 static ssize_t store_engine_load(struct device *dev,
562 			     struct device_attribute *attr,
563 			     const char *buf, size_t len, int nr)
564 {
565 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
566 	struct lp55xx_chip *chip = led->chip;
567 	int ret;
568 
569 	mutex_lock(&chip->lock);
570 
571 	chip->engine_idx = nr;
572 	lp5523_load_engine_and_select_page(chip);
573 	ret = lp5523_update_program_memory(chip, buf, len);
574 
575 	mutex_unlock(&chip->lock);
576 
577 	return ret;
578 }
579 store_load(1)
580 store_load(2)
581 store_load(3)
582 
583 static ssize_t lp5523_selftest(struct device *dev,
584 			       struct device_attribute *attr,
585 			       char *buf)
586 {
587 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
588 	struct lp55xx_chip *chip = led->chip;
589 	struct lp55xx_platform_data *pdata = chip->pdata;
590 	int i, ret, pos = 0;
591 	u8 status, adc, vdd;
592 
593 	mutex_lock(&chip->lock);
594 
595 	ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
596 	if (ret < 0)
597 		goto fail;
598 
599 	/* Check that ext clock is really in use if requested */
600 	if (pdata->clock_mode == LP55XX_CLOCK_EXT) {
601 		if  ((status & LP5523_EXT_CLK_USED) == 0)
602 			goto fail;
603 	}
604 
605 	/* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
606 	lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL, LP5523_EN_LEDTEST | 16);
607 	usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
608 	ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
609 	if (ret < 0)
610 		goto fail;
611 
612 	if (!(status & LP5523_LEDTEST_DONE))
613 		usleep_range(3000, 6000); /* Was not ready. Wait little bit */
614 
615 	ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &vdd);
616 	if (ret < 0)
617 		goto fail;
618 
619 	vdd--;	/* There may be some fluctuation in measurement */
620 
621 	for (i = 0; i < LP5523_MAX_LEDS; i++) {
622 		/* Skip non-existing channels */
623 		if (pdata->led_config[i].led_current == 0)
624 			continue;
625 
626 		/* Set default current */
627 		lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
628 			pdata->led_config[i].led_current);
629 
630 		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0xff);
631 		/* let current stabilize 2 - 4ms before measurements start */
632 		usleep_range(2000, 4000);
633 		lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL,
634 			     LP5523_EN_LEDTEST | i);
635 		/* ADC conversion time is 2.7 ms typically */
636 		usleep_range(3000, 6000);
637 		ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
638 		if (ret < 0)
639 			goto fail;
640 
641 		if (!(status & LP5523_LEDTEST_DONE))
642 			usleep_range(3000, 6000);/* Was not ready. Wait. */
643 
644 		ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &adc);
645 		if (ret < 0)
646 			goto fail;
647 
648 		if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
649 			pos += sprintf(buf + pos, "LED %d FAIL\n", i);
650 
651 		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0x00);
652 
653 		/* Restore current */
654 		lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
655 			led->led_current);
656 		led++;
657 	}
658 	if (pos == 0)
659 		pos = sprintf(buf, "OK\n");
660 	goto release_lock;
661 fail:
662 	pos = sprintf(buf, "FAIL\n");
663 
664 release_lock:
665 	mutex_unlock(&chip->lock);
666 
667 	return pos;
668 }
669 
670 static void lp5523_led_brightness_work(struct work_struct *work)
671 {
672 	struct lp55xx_led *led = container_of(work, struct lp55xx_led,
673 					      brightness_work);
674 	struct lp55xx_chip *chip = led->chip;
675 
676 	mutex_lock(&chip->lock);
677 	lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + led->chan_nr,
678 		     led->brightness);
679 	mutex_unlock(&chip->lock);
680 }
681 
682 static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
683 static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
684 static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
685 static LP55XX_DEV_ATTR_RW(engine1_leds, show_engine1_leds, store_engine1_leds);
686 static LP55XX_DEV_ATTR_RW(engine2_leds, show_engine2_leds, store_engine2_leds);
687 static LP55XX_DEV_ATTR_RW(engine3_leds, show_engine3_leds, store_engine3_leds);
688 static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
689 static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
690 static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
691 static LP55XX_DEV_ATTR_RO(selftest, lp5523_selftest);
692 
693 static struct attribute *lp5523_attributes[] = {
694 	&dev_attr_engine1_mode.attr,
695 	&dev_attr_engine2_mode.attr,
696 	&dev_attr_engine3_mode.attr,
697 	&dev_attr_engine1_load.attr,
698 	&dev_attr_engine2_load.attr,
699 	&dev_attr_engine3_load.attr,
700 	&dev_attr_engine1_leds.attr,
701 	&dev_attr_engine2_leds.attr,
702 	&dev_attr_engine3_leds.attr,
703 	&dev_attr_selftest.attr,
704 	NULL,
705 };
706 
707 static const struct attribute_group lp5523_group = {
708 	.attrs = lp5523_attributes,
709 };
710 
711 /* Chip specific configurations */
712 static struct lp55xx_device_config lp5523_cfg = {
713 	.reset = {
714 		.addr = LP5523_REG_RESET,
715 		.val  = LP5523_RESET,
716 	},
717 	.enable = {
718 		.addr = LP5523_REG_ENABLE,
719 		.val  = LP5523_ENABLE,
720 	},
721 	.max_channel  = LP5523_MAX_LEDS,
722 	.post_init_device   = lp5523_post_init_device,
723 	.brightness_work_fn = lp5523_led_brightness_work,
724 	.set_led_current    = lp5523_set_led_current,
725 	.firmware_cb        = lp5523_firmware_loaded,
726 	.run_engine         = lp5523_run_engine,
727 	.dev_attr_group     = &lp5523_group,
728 };
729 
730 static int lp5523_probe(struct i2c_client *client,
731 			const struct i2c_device_id *id)
732 {
733 	int ret;
734 	struct lp55xx_chip *chip;
735 	struct lp55xx_led *led;
736 	struct lp55xx_platform_data *pdata;
737 	struct device_node *np = client->dev.of_node;
738 
739 	if (!dev_get_platdata(&client->dev)) {
740 		if (np) {
741 			ret = lp55xx_of_populate_pdata(&client->dev, np);
742 			if (ret < 0)
743 				return ret;
744 		} else {
745 			dev_err(&client->dev, "no platform data\n");
746 			return -EINVAL;
747 		}
748 	}
749 	pdata = dev_get_platdata(&client->dev);
750 
751 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
752 	if (!chip)
753 		return -ENOMEM;
754 
755 	led = devm_kzalloc(&client->dev,
756 			sizeof(*led) * pdata->num_channels, GFP_KERNEL);
757 	if (!led)
758 		return -ENOMEM;
759 
760 	chip->cl = client;
761 	chip->pdata = pdata;
762 	chip->cfg = &lp5523_cfg;
763 
764 	mutex_init(&chip->lock);
765 
766 	i2c_set_clientdata(client, led);
767 
768 	ret = lp55xx_init_device(chip);
769 	if (ret)
770 		goto err_init;
771 
772 	dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
773 
774 	ret = lp55xx_register_leds(led, chip);
775 	if (ret)
776 		goto err_register_leds;
777 
778 	ret = lp55xx_register_sysfs(chip);
779 	if (ret) {
780 		dev_err(&client->dev, "registering sysfs failed\n");
781 		goto err_register_sysfs;
782 	}
783 
784 	return 0;
785 
786 err_register_sysfs:
787 	lp55xx_unregister_leds(led, chip);
788 err_register_leds:
789 	lp55xx_deinit_device(chip);
790 err_init:
791 	return ret;
792 }
793 
794 static int lp5523_remove(struct i2c_client *client)
795 {
796 	struct lp55xx_led *led = i2c_get_clientdata(client);
797 	struct lp55xx_chip *chip = led->chip;
798 
799 	lp5523_stop_all_engines(chip);
800 	lp55xx_unregister_sysfs(chip);
801 	lp55xx_unregister_leds(led, chip);
802 	lp55xx_deinit_device(chip);
803 
804 	return 0;
805 }
806 
807 static const struct i2c_device_id lp5523_id[] = {
808 	{ "lp5523",  LP5523 },
809 	{ "lp55231", LP55231 },
810 	{ }
811 };
812 
813 MODULE_DEVICE_TABLE(i2c, lp5523_id);
814 
815 #ifdef CONFIG_OF
816 static const struct of_device_id of_lp5523_leds_match[] = {
817 	{ .compatible = "national,lp5523", },
818 	{},
819 };
820 
821 MODULE_DEVICE_TABLE(of, of_lp5523_leds_match);
822 #endif
823 
824 static struct i2c_driver lp5523_driver = {
825 	.driver = {
826 		.name	= "lp5523x",
827 		.of_match_table = of_match_ptr(of_lp5523_leds_match),
828 	},
829 	.probe		= lp5523_probe,
830 	.remove		= lp5523_remove,
831 	.id_table	= lp5523_id,
832 };
833 
834 module_i2c_driver(lp5523_driver);
835 
836 MODULE_AUTHOR("Mathias Nyman <mathias.nyman@nokia.com>");
837 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
838 MODULE_DESCRIPTION("LP5523 LED engine");
839 MODULE_LICENSE("GPL");
840